<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>

<body>
    <script>
        var m = 1,
            j = k = 0;

        function add(n) {
            return n = n + 1;
        }
        y=add(m);
        function add(n){
            return n=n+3;
        }
        z=add(m);
        console.log(y);
        console.log(z);
    </script>                                                                                                                                                                                                                                   
</body>

</html>